Mozilla's Firefox OS continues its slow march across the globe, with carriers set to begin shipping devices running the open source, browser-based smartphone platform in additional developed markets this week.

Spanish telecoms giant Telefónica has previously sold Firefox OS phones in Spain, but the bulk of its efforts have been focused on its subsidiaries in Spanish-speaking emerging markets, including Colombia, Mexico, Peru, Uruguay, and Venezuela.

Beginning on Thursday, however, Telefónica began taking preorders for the Alcatel Onetouch Fire E in Germany under its O2 brand.

The Onetouch Fire E is the second Firefox OS phone from Alcatel and the first to deliver what Mozilla has termed "mid-tier hardware" for the platform. It features a 1.2GHz dual-core processor – likely a Qualcomm Snapdragon MSM8210 SoC, judging by Mozilla's reference hardware – plus a 4.5-inch display running at 960-by-540 resolution, 512MB RAM, and 4GB of storage.

It's hardly groundbreaking kit, judging by modern smartphone standards. But if the Onetouch Fire E's specs don't match those of today's Android and iOS devices, neither does its price. Telefónica is selling it for just €29 with the purchase of a wireless plan.

Telefónica isn't the only wireless operator that's interested in bringing Firefox OS to Germany, either. Deutsche Telekom has announced that it, too, will sell the Alcatel Onetouch Fire E in the country under its Congstar discount brand – and while Telefónica won't begin shipping the devices to customers until August, Congstar will have them in shops this week.

Chinese device maker ZTE has also said that it will launch the ZTE Open C in France later this month, but no carrier partner has been announced.

Meanwhile, Firefox OS is poised to continue to expand around the globe throughout the rest of the year, maintaining its emphasis on developing markets.

Deutsche Telekom, for example, has said that it plans to launch Firefox OS devices in Croatia, Czech Republic, Macedonia, and Montenegro in the coming months. Telefónica, on the other hand, says it will offer Firefox OS kit across all of its Latin American markets by the end of the year, including in Central America, Argentina, and Ecuador. And Carlos Slim's América Móvil says it will expand its Firefox OS efforts beyond Mexico into Latin America this year, as well.

The Asia-Pacific region comes next. Indian carriers Intex and Spice have both said they will "soon" offer Firefox OS handsets "in the ultra-low-cost category," which could mean devices priced as low as $25. Chunghwa Telecom has signed on for Taiwan. And Telenor has announced plans to begin selling Firefox OS devices in Asia by the end of the year; the Norwegian firm currently operates in Bangladesh, India, Malaysia, Myanmar, Pakistan, and Thailand.

It's a good showing for what has been widely perceived as a quixotic effort on Mozilla's part. Despite having launched the first Firefox OS devices just one year ago, Mozilla says the platform is now available on seven different smartphone models in 15 different countries – and judging by this week's announcements, there is much more to come. ®